Pokemon Black/White in game Zoroark event.

If you send over either Suicune, Entei, or Raikou to Black/White form the 13th Pokemon movie, you will get acess to a special Zoroark battle.

New info has been found about this event. It has been confirmed that Zoroark will already be using Illusion when you start the battle. If you send over Raikou Zoroark will be Entei. If you send over Entei Zoroark will be Suicune. If you send over Suicune Zoroark will be Raikou. It was also confirmed that the only way to obtain Zorua/Zoroark is through these special events. It is not currentley known how Zoroarks ability will work outside of this battle.